Conventionally, there is known a magnetic ink character reading apparatus that is provided with a magnetic head for outputting a signal in accordance with a variation in a magnetic flux caused by a Magnetic Ink Character Recognition (MICR) characters. The magnetic ink character reading apparatus performs a character recognition processing based on a signal data string corresponding to the output signal of the magnetic head to recognize a magnetic ink character string recorded on a recording medium.
This type of magnetic ink character reading apparatus serves to read a character string of a predetermined format (a character number or the like) printed on a sheet with magnetic ink characters.
For example, for payment by check at a retail store, there is used a magnetic ink character reading apparatus which has a function to read a magnetic ink character string printed on a sheet and a function to print an image on a sheet. A salesperson in a retail store receives a check from a customer, and prints store identification information, purchase price, and the like, on the check by the magnetic ink character reading apparatus. Then, the customer confirms the store identification information, purchase price and the like printed on the check and signs his or her name on the check. And, the salesperson allows the magnetic ink character reading apparatus to read an account number and the like printed with magnetic ink characters on the surface of the check. Thus read account number and the like are transmitted to a host computer for confirming the validity of the account number. When the validity of the account number and the like are confirmed, the confirmation of the validity is printed on the check, which completes the payment by the check.
However, there happens a case where, although a character string of a predetermined format should be originally printed, a part of the character string is not printed due to some error made in the printing process.
For example, in a case where a 12-character character string as shown in FIG. 20 should be printed, there happens a case where one of the characters is missing, for example, as shown in FIG. 21. Also, even when all of the characters of a character string are printed, there happens a case where the character string is partially printed faint.
In these cases, the character string obtained as the result of recognition by the magnetic ink character reading apparatus does not provide a character string that conforms to a predetermined format, but some of the character string is missing. Here, in the magnetic ink character reading apparatus, the magnetic ink characters recorded on the recording medium are recognized one by one. Therefore, in the above-mentioned cases, whether or not the recognized character string conforms to the predetermined format is found only after completion of the character recognition processing. Accordingly, in the above-mentioned cases, the magnetic ink character reading apparatus uselessly performs the character recognition processing.